Kinect, Move, Wii Motion Plus, Playstation Eye, the issue is that developers are more wary to make games for a potential gimmick.
On a completely unrelated note: Skyward Sword. I read in an interview that its supposed to have a ridiculous amount of play time and content, more than OoT, MM, or anything else by far. We can sit here and argue how a tree looks for hours, but one thing's for sure: Nintendo wins at gameplay. And if the content holds true to what they're saying, im totally pumped for it.